PostGIS  2.1.10dev-r@@SVN_REVISION@@
PG_FUNCTION_INFO_V1 ( RASTER_getPixelWidth  )

Return the pixel width of the raster.

The pixel width is a read-only, dynamically computed value derived from the X Scale and the Y Skew.

Pixel Width = sqrt( X Scale * X Scale + Y Skew * Y Skew )